NAPCO Coil Balance System Help

A handy person from Holland, PA says:
NAPCO Tilt in window. Unit shown was a replacement sent to me several years ago by local wholesaler now out of business. The broken unit has letter "F" stamped on it. Other than the different stamp on it, it appears identical. I need both left and right sides.
Thumbnail of the uploaded file named 01FAA725-4338-42C6-87E0-F2742C311668.jpeg
Thumbnail of the uploaded file named 0CC7289C-FD77-497E-BD23-4103BAEA50B3.jpeg
Thumbnail of the uploaded file named E9E4450C-3039-4DBE-B740-E3801AF69CD9.jpeg
Profile picture of Bob
Bob from SWISCO responded:

Thanks for posting. The pivot shoe used with these coil balances is a bit unusual. It looks like our 15-175, but it has an exceptionally big brake; it also looks like the metal cam may be deeper as well. I'm checking with my senior colleagues to make sure we recommend the right item or course of action for you to proceed. We'll get back to you as soon as we can with more details. Thanks for bearing with us.

Profile picture of Paul
Paul from SWISCO responded:

Your photos gives us an appearance of are large thick shoe, but I believe the dimesions are 1-1/4" wide by 9/16". Please confirm. If so, then disregard Bob's concerns. You would need our 15-175 with the the slate blue brake. The 1/2" wide coil spring you show with the letter "C" would be our S152-3 and for the "F" it would be S152-6. Let me know if you have any other inquiries. 

A handy person from Holland, PA says:

Paul, you are correct on the dimensions. Thank you for your expertise. One other question: After reading over your comments carefully, I realize I will have to put the unit together. Since it's a double coil, I'll need two coils per unit, correct?

Profile picture of Paul
Paul from SWISCO responded:

Yes. Based on the stamps on your old coil springs, you would need one of the S152-3 and one of the S152-6 on each side of the window sash.

A handy person from Holland, PA says:
Can you also tell me what coils CL and B correspond to?
Profile picture of Bob
Bob from SWISCO responded:

Not every stamp code on a coil spring has significance. The 'C' could still translate to 3 lbs, for instance; but there is no 2 lb Series 152 spring, so the B means nothing to us. If in doubt, give us the exact weight of the window sash, and we'll work out what you need. 

Reply to Thread
Use this form to ask a follow-up question or to share your experience regarding this subject.
(your email address will be kept private and is only used to inform you when a response has been made)